[Manav Bhathal]"Could you refer me to a guide on the best way to set up scratch disks and hardrives to edit?"

There is really nothing to do under Premiere. You can make it keep all the generated files (like the audio conforming) with the project, but I found that makes for a messy project folder. Plus, all your renders and autosaves are automatically put in your main project folder, and that's the bigger stuff.

The codec options you list are quite limited. What version of Premiere are you on?